This application claims priority from Korean Patent Application No. 2004-16798, filed on Mar. 12, 2004, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to transcoding of moving pictures, and more particularly, to a transcoding method and apparatus, which convert moving picture data from one encoding format to another encoding format, and a motion vector interpolation method therefor.
2. Description of the Related Art
Recent developments in computer and communications technologies have enabled considerable amounts of multimedia data to be transmitted via networks. Accordingly, various methods for encoding multimedia data and transmitting the multimedia data over a network have been suggested. Since a sending party and a receiving party, between which multimedia data are transmitted, are more likely to be under different circumstances, the multimedia data needs to be converted from one encoding format to another encoding format in consideration of the quality-of-service of each of the sending and receiving parties. This type of conversion is called transcoding. A video transcoding method includes a pixel-domain transcoding method and a frequency-domain transcoding method, (e.g., a discrete cosine transform (DCT)-domain transcoding method).
In order to perform a pixel-domain transcoding process on moving picture data, it is necessary to decode and then encode the moving picture data, in which case, motion estimation should be re-executed on each macroblock of each frame of the moving picture data. Therefore, it takes much time to transcode the moving picture data, and it is difficult to transmit the transcoded moving picture data in real time.